The Doppler effect occurs when

Question

a) a source of sound moves toward a listener
b) a listener moves toward a source of sound
c) a listener and a source of sound move away from each other
d) a listener and a source of sound move toward each other.
e) all of the above

e--all of the above.

Answer 1

The Doppler effect occurs in all of the above situations. It is a change in frequency or wavelength of a wave in relation to an observer who is moving relative to the source of the wave.